Réponse:
1- A= (2y-4)(3-5y) - (4-y)(2y-4)
A= 6y-10y^2-12+20y - (8y-16-2y^2+4y)
A= 6y-10y^2-12+20y-8y+16+2y^2-4y
A= -8y^2+14y+4
2- A= (2y-4)(3-5y) - (4-y)(2y-4)
A= (2y-4)(3-5y-(4-y))
A= (2y-4)(3-5y-4+y)
A= (2y-4)(-4y-1)
3- y= -2
A= (2y-4)(-4y-1)
A= (2*(-2)-4)(-4*(-2)-1)
A= -8*(-8)
A= 64
^2 signifie carré
* c'est le multiplier
